I love self patterning or self striping yarn, it takes all the hassle out of changing colours when knitting and I love to watch the pattern emerge as I'm working with it.
This is Regia World College Color in Bachelor, a yarn which is now discontinued. I usually knit socks in 4 ply but this is thicker, perfect for wearing inside boots in winter. The ribbed Thuja pattern also gives the socks a bit more bulk and pads them out.
When I use a self striping yarn for socks, I try to match each sock. As you can see, I nearly managed it, there's just a little more red on one toe than the other.
It's been quite a while between knitting my last pair of socks and these, but I'm back in the swing of sock knitting again so I don't think it'll be long before I'm casting on my next pair.